Commit 823e7e8c authored by FUJITA Tomonori's avatar FUJITA Tomonori Committed by Ingo Molnar
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x86: dma_alloc_coherent sets gfp flags properly 



Non real IOMMU implemenations (which doesn't do virtual mappings,
e.g. swiotlb, pci-nommu, etc) need to use proper gfp flags and
dma_mask to allocate pages in their own dma_alloc_coherent()
(allocated page need to be suitable for device's coherent_dma_mask).

This patch makes dma_alloc_coherent do this job so that IOMMUs don't
need to take care of it any more.

Real IOMMU implemenataions can simply ignore the gfp flags.

Signed-off-by: default avatarFUJITA Tomonori <fujita.tomonori@lab.ntt.co.jp>
Acked-by: default avatarJoerg Roedel <joerg.roedel@amd.com>
Signed-off-by: default avatarIngo Molnar <mingo@elte.hu>
parent 8a53ad67

arch/x86/kernel/pci-nommu.c

+2 −17
Original line number Diff line number Diff line
@@ -80,26 +80,11 @@ nommu_alloc_coherent(struct device *hwdev, size_t size, 
	int node;

	struct page *page;



	gfp |= __GFP_ZERO;



	dma_mask = hwdev->coherent_dma_mask;

	if (!dma_mask)

		dma_mask = *(hwdev->dma_mask);

	dma_mask = dma_alloc_coherent_mask(hwdev, gfp);



	if (dma_mask < DMA_24BIT_MASK)

		return NULL;

	gfp |= __GFP_ZERO;



	node = dev_to_node(hwdev);



#ifdef CONFIG_X86_64

	if (dma_mask <= DMA_32BIT_MASK && !(gfp & GFP_DMA))

		gfp |= GFP_DMA32;

#endif



	/* No alloc-free penalty for ISA devices */

	if (dma_mask == DMA_24BIT_MASK)

		gfp |= GFP_DMA;



again:

	page = alloc_pages_node(node, gfp, get_order(size));

	if (!page)

include/asm-x86/dma-mapping.h

+28 −4
Original line number Diff line number Diff line
@@ -239,6 +239,29 @@ static inline int dma_get_cache_alignment(void) 
	return boot_cpu_data.x86_clflush_size;

}



static inline unsigned long dma_alloc_coherent_mask(struct device *dev,

						    gfp_t gfp)

{

	unsigned long dma_mask = 0;



	dma_mask = dev->coherent_dma_mask;

	if (!dma_mask)

		dma_mask = (gfp & GFP_DMA) ? DMA_24BIT_MASK : DMA_32BIT_MASK;



	return dma_mask;

}



static inline gfp_t dma_alloc_coherent_gfp_flags(struct device *dev, gfp_t gfp)

{

	unsigned long dma_mask = dma_alloc_coherent_mask(dev, gfp);



#ifdef CONFIG_X86_64

	if (dma_mask <= DMA_32BIT_MASK && !(gfp & GFP_DMA))

		gfp |= GFP_DMA32;

#endif

       return gfp;

}



static inline void *

dma_alloc_coherent(struct device *dev, size_t size, dma_addr_t *dma_handle,

		gfp_t gfp)
@@ -259,10 +282,11 @@ dma_alloc_coherent(struct device *dev, size_t size, dma_addr_t *dma_handle, 
	if (!dev->dma_mask)

		return NULL;



	if (ops->alloc_coherent)

		return ops->alloc_coherent(dev, size,

				dma_handle, gfp);

	if (!ops->alloc_coherent)

		return NULL;



	return ops->alloc_coherent(dev, size, dma_handle,

				   dma_alloc_coherent_gfp_flags(dev, gfp));

}



static inline void dma_free_coherent(struct device *dev, size_t size,

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